A U.S. agency has lined up broad support for its plan to end the government's oversight of the Internet's domain name system, despite opposition from some Republicans in Congress.

The U.S. National Telecommunications and Information Administration (NTIA) on Thursday released statements of support for a plan to end its oversight of the Internet Corporation for Assigned Names and Numbers (ICANN).

Among supporters of a plan, developed by the ICANN community, to transition ICANN's domain name coordination functions to a multistakeholder governance model are Amazon.com, Google, Cisco Systems, Microsoft, Facebook, Hewlett Packard Enterprise, the U.S. Chamber of Commerce, and the Computer and Communications Industry Association.

NTIA on Thursday announced it had reviewed the community proposal and found it meets the agency's criteria for allowing the ICANN privatization plan to move forward. The community plan maintains the openness of the Internet and maintains the security and stability of the DNS, said NTIA Administrator Lawrence Strickling. It does not replace NTIA's oversight with another government organization, he said, although that's been a fear of some critics of the NTIA plan.

The NTIA's approval of the community's transition plan sets up a clash between some Republicans in Congress and the agency and its supporters. On Wednesday, Republicans in Congress introduced legislation that would prohibit any transfer of Internet domain name system functions except if expressly allowed by lawmakers.

The U.S. government oversight of ICANN helps protect it "from authoritarian regimes that view the Internet as a way to increase their influence and suppress freedom of speech," Senator Ted Cruz, a Texas Republican and sponsor of the bill, said in a statement. "This issue threatens not only our personal liberties but also our national security."

NTIA's contract with ICANN that gives the agency oversight of the Internet Assigned Numbers Authority (IANA) functions -- including responsibility for the coordination of the DNS root, IP addressing, and other Internet protocol resources -- expires in September, but it could be extended if the agency's conditions for a transition aren't met.

The community's transition plan, however, is a good one, supporters said. The NTIA first proposed to end its oversight of ICANN in March 2014, but the U.S. government has promised since the late 1990s that it would eventually give up that role.

Critics who say the NTIA is giving away the Internet are making a "troubling" argument, Matthew Shears, director of global Internet policy at the Center for Democracy and Technology, wrote in a recent blog post. A delay in the transition would signal to other countries that government control is still on the table, he wrote.

"Governments that want to see the transition fail will use the extension and continued U.S .government involvement as justification to promote further intergovernmental control over the internet," Shears added. "The longer the U.S. government retains its role, the more the voices against multistakeholder approaches and an open internet will grow."

Early ICANN transition critic Steve DelBianco, executive director of e-commerce trade group NetChoice, also voiced support for the community transition plan.

With Thursday's report, the NTIA "clears the way for expiration of the IANA contract, leaving ICANN under the control of the international private sector stakeholders it was designed to serve," DelBianco said in a statement. "Some members of Congress have lingering doubts about this transition, but the protections are in place -- to include ICANN's headquarters remaining in the U.S. -- to ensure that free expression and free enterprise will prevail in the domain name system at the core of the Internet."